This has been a good thread. Hope it keeps going a while.

To those who see the advantage of FPTP as promoting rapid change and decisive governance (an argument only relevant to parliamentary systems, and not to the US with its separation of powers) I would ask two things:

1. Is it good to get rapid change that has been endorsed by much less than 50% of the electorate? Perhaps we should consider major changes in the policy realm that are endorsed by 40-some percent (or even less) as less than desirable.

2. Can't a single-party government just as easily resist needed change as promote it? The Muldoon government in New Zealand before 1984 is a good example. It ignored the swelling deficits and inefficiencies in the economy, letting the crisis worsen, and it had twice been outvoted by Labour. It did not even represent a plurality of the NZ electorate.

To those who worry about small parties holding too much power under PR, I don't see it. For that to happen, it seems you need (1) the party in question to have a really secure constituency with narrow demands and be (2) utterly unprincipled in who it makes coalitions with. Some of the small religious parties in Israel (where the threshold is very low) might be examples.

But in most multiparty systems--and I think this applies to Germany and New Zealand, as well as Norway (which also just had a very close election)--even the little parties have constituencies that are more fluid at the same time that they have principled policy stances. If such a party demands too much it risks losing voters, possibly to one of the bigger parties, or another small party that is not seen as trying to hold everyone else "hostage."

And if there is only one major party or bloc that the small party can credibly make a coalition with, then it is much more constrained in what it can demand in exchange for its support. Otherwise it risks a very bad outcome for its voters: the seating of a government from the other side.